From: William Djaja Tjokroaminata <billtj@...>
Date: 2002-01-26T07:32:19+09:00
Subject: Re: Serious Array Bug in Ruby 1.6.6?

Christoph,

Thank you, thank you for summarizing it quite well.  For me with C/C++
background, it is much easier to just say all Ruby references or variables
are pointers (except the FixNum, True, etc.)  So basically Ruby only
supports

    ...
    pointer = &(new (object));
    vector a = new (n, pointer);

and not

    vector a = new (n, object);

(excuse me if the syntax is wrong; I have not used C++ for a long time).

Yes, the List class is exactly what I want.  I don't see why it is so
inefficient, because the opposite is I still don't see the use of an array
of pointers to the same object.  If it is so inefficient, why just don't
provide it to the user: Array.new (n, obj) only works for obj of FixNum,
True, Nil, etc.  On the other hand, if it is allowed for obj to be a Hash,
then why not create multiple hashes instead of just a single hash.

Ruby has done a lot of checkings, like public/protected/private methods,
and attr_reader/attr_accessor methods.  For Array, why not just check the
type/class of obj when the array is created, just like what you do
for singleton?  If a program has to create and destroy arrays many many
times, probably it should have been written in C.

Regards,

Bill
===========================================================================
Chr. Rippel <chr_news@gmx.net> wrote:
> Actually Rubys Arrays are an abstraction of an C/C++ array of pointers.
> What you really want is a List class free of side-effects

> ----
> class Object
>   def _dup
>     begin
>       dup
>     rescue TypeError
>       self   # for classes implementing the Singleton pattern
>     end
>   end
> end

> class List < Array
>     def initialize (nums, ini = nil)
>         super(nums).collect! do |e| e._dup end
>     end
>     def []=(l,r)
>         super (l,r._dup)
>     end
>     def [](l)
>         super(l)._dup
>     end
>  end
> ----

> Yes lists are great but they are also terribly inefficient and even
> functional languages need to introduce Ruby-type Arrays through
> the back door.

> /Christoph